The present invention relates generally to breathers for liquid reservoirs. More particularly, the present invention relates to humidity controlling breathers for liquid reservoirs.
Breathers allow for expansion of liquids and gases (e.g., air) in liquid (e.g., lubricant) reservoirs while preventing contamination of the liquid. For liquid reservoirs such as engine crank cases and lubricant storage reservoirs, water vapor and dust particles in the air can be pulled into the liquid by the expansion and contraction action of the air and liquid in the reservoir with changes in temperature or barometric pressure of the surrounding environment and the contents of the reservoir (i.e., fluid level changes in the reservoir). Currently, breathers are replaced on a schedule, whether the breathers are at the end of their useful life or not because it is difficult to tell when a breather has reached the end of its useful life. Alternatively, breathers utilize color changing desiccants to indicate when the breather has reached the end of its useful life and needs replacement. The color changing desiccants require transparent breather housings which are generally weaker than opaque breather housings, present chemical incompatibility issues, and the chemicals used to change color may be considered toxic under some guidelines. Further, the color change may be faint, difficult to see depending on the location and environment of the reservoir and breather, and therefore difficult to interpret. For example, breather dryers (e.g., desiccant breathers) are commonly mounted on lubricating fluid reservoirs in large format wind turbines. The nacelles in these turbines are typically cramped and include many poorly lit, hard to reach areas near lubrication reservoirs where breathers are located. Visibility of the breather and any color change is therefore difficult to see. Additionally, the nacelle may typically only be accessed when the wind turbine is shut down (i.e., stopped and not generating power).